BACKGROUND: There is a high degree of comorbidity between
fibromyalgia and major depression. The latter is characterized
by signs of immune activation, whereas the immune status in
fibromyalgia is not yet elucidated. The aims of the present
study were to examine (i) neopterin and biopterin excretion in
24-h urine of patients with fibromyalgia compared with normal
volunteers and patients with major depression; and (ii) the
effects of subchronic treatment with sertraline (11 weeks) on
the urinary excretion of neopterin and biopterin.

METHODS:
Measurements of neopterin, biopterin, pseudouridine,
creatinine and uric acid in 24- h urine were performed by
means of HPLC in 14 fibromyalgia and ten major depressed
patients and 17 normal volunteers.

RESULTS: There were no
significant differences in urine excretion of the above five
analytes between patients with fibromyalgia and normal
volunteers. Patients with major depression showed
significantly higher urinary neopterin excretion than normal
volunteers and fibromyalgia patients. Patients with
fibromyalgia and major depression had a significantly
increased neopterin/creatinine ratio. Fibromyalgia patients
had significantly lower urinary excretion of creatinine than
patients with major depression. In fibromyalgia patients,
there were no significant effects of sertraline treatment on
any of the urine analytes.

CONCLUSIONS: The findings suggest
that fibromyalgia, in contrast to major depression, may not be
accompanied by activation of cell-mediated immunity.

LIMITATION: Other immune markers should be measured in
fibromyalgia before drawing definite conclusions.

CLINICAL RELEVANCE: Increased urinary excretion of neopterin
can be used as a marker for major depression, but not fibromyalgia.